Banding NPR shader

[Isleofgough]

How would I set up a shader to create non photorealistic banding based on luminosity remapped to a stepped color ramp? Here are C4D and Modo shaders that get that effect:

 

 

 

 

 

Edited May 21, 2018 by Isleofgough

[konstantin magnus]

Hi Philo,

its just a start, but I set up a diffuse shader that quantizes lighting using the output of a pbrlighting-node. Make sure to set your render view to the 'cartoon' channel.

cartoon_shader.hiplc

Edited May 26, 2018 by konstantin magnus

[Isleofgough]

That is PERFECT!! I tried to modify the color toon shader, but it is not something that can be easily altered to quantize more than three levels. I will look at the details to see how you made this, but it works great! Quick question, though: I assume your shader doesn't read your color data? It looks like your color is derived from the texture map.

Edited May 26, 2018 by Isleofgough

[konstantin magnus]

On 26.5.2018 at 4:24 PM, Isleofgough said:

It looks like your color is derived from the texture map.

Yes, true. Because I thought thats what you wanted.

You can always connect a parameter node with "Cd" to the color input of pbrdiffuse, though.

[Isleofgough]

Thank you. I am still trying to get my head around shader nodes. I find them less intuitive than geometry nodes and am looking for free or paid tutorials to understand them better. I really appreciate your example. I looked at the toon outline and toon color shader’s internal structure and they are formidable. In addition, the outline shader doesn’t work right if the copy or instance has a principled shader. Sidefx has registered this as a bug, but I’m sure the solution is in the nodes.

[konstantin magnus]

Here is another cartoon shader based on lambertian shading and a color ramp.

And a quick tutorial on it, as well:

cartoon_shader_4.hiplc

Edited June 4, 2018 by konstantin magnus

[Isleofgough]

That is very helpful! Building shaders is not something i’ve had to do in other 3D programs excepting connecting some intuitive nodes. Other programs with npr shaders generally have outline features as well, but in Houdini this is a separate shader that has to be assigned to instance or copy - and it works only when the other is assigned a cartoon color shader. The prebuilt toon color shader doesn’t have many options, so your tutorial on building it manually is invaluable!